3281581 has 4 divisors (see below), whose sum is σ = 3323200. Its totient is φ = 3239964.

The previous prime is 3281573. The next prime is 3281627. The reversal of 3281581 is 1851823.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1851823 = 89 ⋅20807.

It is a cyclic number.

It is not a de Polignac number, because 3281581 - 2³ = 3281573 is a prime.

It is a super-2 number, since 2×3281581² = 21537547719122, which contains 22 as substring.

It is a Duffinian number.

3281581 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3281081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20691 + ... + 20848.

It is an arithmetic number, because the mean of its divisors is an integer number (830800).

Almost surely, 2^3281581 is an apocalyptic number.

It is an amenable number.

3281581 is a deficient number, since it is larger than the sum of its proper divisors (41619).

3281581 is an equidigital number, since it uses as much as digits as its factorization.

3281581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41618.

The product of its digits is 1920, while the sum is 28.

The square root of 3281581 is about 1811.5134556497. The cubic root of 3281581 is about 148.6030453194.

It can be divided in two parts, 32815 and 81, that added together give a triangular number (32896 = T₂₅₆).

The spelling of 3281581 in words is "three million, two hundred eighty-one thousand, five hundred eighty-one".